In recent years, substantial effort has been devoted to the provision of solid-state inverters for use with induction heating equipment. This effort has presented substantial technical difficulties in that the inverter concept is more applicable to use with a load that has a fixed impedance and requires a generally fixed power factor for operating the inverter. In induction heating, a fixed load is not possible. Workpieces of different sizes, different compositions are to be inductively heated by the inverter. Rapid heating cycles for workpieces are different to varying degrees and cause the inverter to experience substantial load changes. In addition, as a workpiece is being heated inductively, its permeability changes. This causes a change in reflected impedance during heating of a single workpiece. In many instances, the inverter is actuated without a workpiece in the coil. This causes still a further variation in the power factor for a given frequency. All of these variations in the load applied across the output of a solid-state inverter, when used for induction heating, cause difficultiesin the field. In some instances, the inverter will not start. When this occurs, an operator must have substantial experience to detect the reason for the inability to energize the inverter. Also, the switching devices in the inverter (SCRs or thyristors) have a turn off time during which a reverse voltage must be applied across the switching device to cause commutation. Fluctuation of the parameters of the load can sometimes prevent turn off and cause damage to the switching devices. If this occurs, the inverter must be repaired. In view of this operating characteristic, inverters generally have some type of circuit for assuring sufficient turn off time of the switching devices is maintained. One of these arrangements is shown in U.S. Pat. No. 3,718,852 wherein the power factor of the load itself is controlled to a desired level so that the necessary turn off time is assured from cycle-to-cycle of the inverter. Thus, in this type of control arrangement, the power factor or phase angle of the current and voltage across the load is detected and compared to a fixed level or phase angle, indicated as R in U.S. Pat. No. 3,718,852. Based upon this comparison, the frequency of the gating oscillator is modified to change the operating frequency of the inverter. The power factor is essentially a desired preselected power factor during operation of the inverter. In practice, the biasing resistor for controlling the reference signal R is 59K ohms. This produces an operating power factor of approximately 0.80 and more specifically 0.78. This power factor is selected to provide a compromise between the desired power factor when the inverter is started up and the desired power factor when the inverter is running. When running, the power factor can be in the neighborhood of 0.90 or even 0.95. Because this high power factor will prevent the inverter from starting up, the reference signal R is modified to about the 0.80 level so that the inverter will start up and continue to run. This compromise is essential because the inverter, which is a parallel compensated inverter, is a current source and is very difficult to start up at high power factors.